Circular knitting machine



Dec. '8, 19170 .1.. s. FoRREsTER CIRCULAR KNIT'TING MACHINE Filed May 2) 1968 Dec. 8, 1970 J. s. FoRREsTER y 3,545,234

CIRCULAR KNITTING MACHINE Filed May 2, 1968 A 3 sheets-sheet z" United States Patent O 3,545,234 CIRCULAR KNITTING MACHINE John S. Forrester, Leicester, England, assignor to Wildt Mellor Bromley Limited, Leicester, England, a British company Filed May 2, 1968, Ser. No. 726,024 Claims priority, application Great Britain, May 10, 1967,

21,614/ 67 Int. Cl. D041) 27/10, 35/10 U.S. Cl. 66-125 6 Claims ABSTRACT OF THE DISCLOSURE A circular knitting machine especially of the multi-feed cylinder and dial type adapted for producing float yarn effects in knitted fabric having iloat controlling units designed not only to ensure engagement of floating yarn by needles intended to take and knit the same at a feed, but also to function as a detector capable of being dellected and withdrawn to an inoperative position in consequence of the exertion laterally thereon of a relatively light pressure as by a broken needle or an undesirable foreign body, or by deliberate manual action.

patterning feed or feeds and, at the or each corresponding feed, only predetermined cylinder needles knit so that unknitted floats extend between these needles. The floating lengths depend upon the numbers of non-knitting cylinder needles which separate those cylinder needles which clear, take yarn and knit.

Depending on the number of feeds and the lengths `of the` floats, it sometimes happens that a floating portion of yarn extending between the feeder at a feed and the lasty needle to knit the yarn is so pulled as to assume an angle which is shallower than the comparatively steeper angle of the stitch cam. If this happens, then the next cylinder needle intended to knit the yarn at the same feed misses the said yarn and so fails to knit it; this is because the yarn floats above the steeply descending head of the needle as the lattter is retracted by the stitch cam to knocking-over point. The yarn so missed is carried round by the last needle to take it to the next feed; meanwhile the old loops on the needles which should have taken the yarn at the previous feed are pressed off and this results in faulty fabric.

It has heretofore been the practice to provide, inimediately after the location of the stitch cam at each feed, or at each relevant feed, of the machine, as the case may be, a spring wire or a blade so arranged as to engage a floating yarn and ensure that it is engaged by the needles descending the stitch cam. But a disadvantage of such wires or blades is that they require to be wholly removed to enable the pattern of the blister fabric to be changed. Moreover, if needle breakage occurs at a time when the wires or blades are in their operative opositions it is likely that some part of a broken needle will collide with the wires or blades and thereby cause considerable damage.

Accordingly, the primary object of the present invention is to provide, in a circular knitting machine of the cylinder and dial type adapted to produce blister fabric, in lieu of wires or blades as heretofore, float control means of an improved form designed to avoid the foregoing disadvantages.

According to this invention a float controller provided for the purposes described in a circular knitting machine of the cylinder and dial type includes an element adapted to be latched and spring loaded in a projected operative position and to be released and retracted under the spring influence to a withdrawn inoperative position as a consequence of the exertion laterally thereon of a relatively light pressure.

The following is a description with reference to the accompanying drawings, of a preferred embodiment of the invention illustrated by way of example as applied to a multi-feed circular knitting machine of the rotary cylinder and dial type.

Referring to the drawings:

FIG. l is an outer elevation of so much of the machine as will suffice to show the connection of the invention therewith and includes two feeds with associated controllers.

FIG. 2 is a vertical sectional elevation taken approximtaely on line A-A of FIG. l.

FIG. 3 is a vertical sectional elevation, on an enlarged scale, of one of the controllers with a yarn controlling element shown retracted.

FIG. 4 is a similar view of the controller with the said element projected.

FIG. 5 shows, per se, the compression spring whereby the controller is loaded.

FIGS. 6 and 7 are respectively enlarged sectional views of part of the yarn controlling element, and

FIG. 8 is a plan view of the controller.

The portion of `the machine shown in FIGS. l and 2- comprises a rotary needle cylinder 1, latch needles 2, a stationary cam box 3 with conventional knitting cam systems 4, a rotary dial 5, a stationary dial cam plate 6, a bed plate 7, and partof an electrical stop motion circuit C.

Mounted on the cam plate 6 at the respective feeds F, F1, are yarn guides 8 of conventional form and associated controllers 9. Each of these controllers includes a yarn controlling element consisting of a shank 10` and a blade 11, and a compression spring 12 so that when the controller is located in the normal position shown in FIGS. l and 2 and loaded, the element 10, 11 projects downwards and is inclined inwards with its blade directed towards the run of the yarn 13 extending between the needles 2 and the yarn guide 8. The path of the yarn when being knitted is shown at the feed F, and the path of the yarn during a long float is shown at the feed F.

Referring especially t0 FIGS. 2, 6 and 7 the blade 11 is enlarged, e.g., made spatulate, and is inwardly shaped or recessed to provide a seating 14 to receive an abnormally floating yarn.

In a specific constructional example of a float control element shown in FIGS. 3 and 4, the major portion of the shank 10 is accommodated within a tubular housing 15 and is surrounded by the helical compression spring 12, the first helix of which is engaged with the shank 10. The last helix 16 of this spring is deformed, c g., offset from its axis as shown in FIG. 5, to such an extent that it is twisted back into closer centering with the spring axis when the spring is placed around the shank 10. A portion of last helix 16 constantly engages a portion of shank 10 which is generally diametrically opposite from a latching detent 19. The shank is of square cross-section and extends through an oblong aperture formed in a base plate 17 located in the recessed lower end of the housing. One side of the shank has formed therein a wedge-shaped recess 18, this providing on the shank the latching detent 19 of saw-tooth form for engagement with the outer surface of the base plate 17- as shown in FIG. 4 at such times as the shank is fully depressed axially so that the blade is projected into its operative position against the action of the compression spring. It is the deformed helix 16 of the spring which laterally biasses the latching detent into engagement with the base plate, over the relevant edge of the oblong aperture therein, the biasing force being provided when the side of the spring, on the side of shank opposite from detent 19, engages the housing as shank 10 is put in the operative position, FIG. 4. But immediately any sideways pressure is exerted upon that side of the shank having thereon the latching detent, the latter will be disengaged from the base plate, thereby triggering otf and releasing the controller element which is thereupon retracted to its inoperative position.

Each of the herein described improved float control controllers may be mounted upon a small bracket attached to any convenient stationary part of a machine having a rotary cylinder and dial, and any convenient rotary part such as the cam box of a machine having a stationary cylinder and dial. Thus, as applied to a multi-feed rotary cylinder and dial machine, the controllers are mounted upon brackets 20 fixed on the stationary dial cam plate 6. In the example shown the controllers are adjustable radially in the brackets and fixed by set screws 21 whereby the blades 11 are accurately set in relation to the needles and the path of the yarn at each feed.

In normal working conditions when the needles are knitting the yarns run just clear of the tips of the operative elements as shown in FIG. 1, but where at any feed a yarn is lmissed by needles, i.e., oat yarn as hereinbefore described, the yarn engages with the Seating 14, as shown in FIGS. 6 and 7, whereby lthe required angular relationship between the yarn and the stitch cam K is maintained.

Thus as in the case of a wire or a blade a spring loaded controller constructed in accordance with the present invention is similarly positioned for engagement with and control of a yfloating yarn suchwise as to hold the latter at an angle adapted to the angle of the stitch cam so that the two are correctly corelated at the relevant feed. But unlike the wire or blade, the improved float control element can be easily moved out of the way, without disturbing its carrier or mounting, and to facilitate, say, a pattern change, simply by pressing it aside and thereby releasing it so that it is automatically retracted to the inoperative position.

Adjunctively, the improved float controller may function to prevent any damage being caused by an undesirable body coming into contact with the aforesaid element in the direction of knitting. Thus, for instance, if any part of a broken needle comes into contact with the controller element the latter is immediately pressed aside and triggered off so that, once again, it is retracted to its withdrawn position under the influence of the released spring loading. The prompt removal of the element from the path of the broken needle precludes the possibility of resulting damage. Similar remarks apply to the presence, on the floating yarn being controlled, of a slab or an obstructive accumulation of lint or lluff.

Each detector moreover is adapted to constitute or incorporates a switch designed to be included in a conventional electric stop motion circuit C. For example the switch comprises an insulator and metal contacts, one combined with the controller element and the other with the insulator and an interposed connector. Thus in the specic constructional embodiment, FIGS. 3 and 4, the switch is made up of a flanged insulating sleeve 22 located in a recess in the upper end of the housing 15, a ilanged metal bush 23 pushed into the sleeve a metal washer 24 between the bush and the shank 10 with a wiring tab 25 between the bush and the sleeve. The shank is tted with a push button or plunger 26 of a plastic or other non-conducting material, eg., screwed on to a screw threaded extension 27 of the shank whereby the washer is also secured. Thus by pressure on the button or plunger the controller is loaded and, at the same time, the switch is opened by separation of the washer 24 from the bush 23 thereby breaking the electrical circuit. In reverse manner when the controller is triggered off the circuit is made under spring action whereby the water is held in Contact with the bush. The circuit shown in FIGS. 1 and 2 and comprises a contact ring 28 to which leads 29 from the tabs 25 are connected by clips 30. The ring is carried by reels 31 attached to brackets 32 mounted in an existing gear housing 33. In this case the ring 28 is connected to a conventional electro-magnetic device or solenoid associated with the stop motion so that release of any one of the elements as a consequence of it being contacted by a broken needle or by a foreign body on the yarn results in' immediate stoppage of the machine. But to enable the controller elements to be retracted deliberately by manual action to out-of-the-way positions, e.g., to facilitate pattern changes, the electrical stop motion circuit would require first to be rendered inoperative.

In the application of the invention to a machine havmg a stationary cylinder and dial the controllers could be mounted on a component arranged for rotation above the dial cam plate or, alternatively, in the proximity of the cam box, with their operative elements downwardly and inwardly inclined as hereinbefore described. As a further alternative, in the case of a rotary cylinder and dial machine, the controllers may be mounted on the cam box with their operative elements disposed as aforesaid.

The invention includes as a feature, a oat controller as hereinbefore described for use, for the purposes specified, in a circular knitting machine of the cylinder and dial type, and it is to be understood that such controllers can also be adapted to control floats between cylinder needles during the production on a cylinder and dial machine of fabrics other than blister fabrics.

I claim:

1. In a circular knitting machine, a needle cylinder, needles operating in the cylinder, a cam box, a knitting cam system in the said cam box, a needle dial, a dial cam cap, a plurality of yarn feeds, and yarn guides at said feeds, capable of being set up for the production of knitted fabric with float yarn effects, the improvement which includes the provision of float controllers, each of which includes an element for controlling the yarn at a feed, and arranged to be disposed in a projected operat1ve position between the needles and the feed so that in normal working conditions when the needles are knitting, the yarn being knitted runs clear of the same element whereas Where the said yarn is missed by the said needles the resulting oat engages the said element suchwise that required angular relationship between the yarn and the corresponding stitch cam at the feed is maintained, a latch for holding the said element in the said operative position, a spring arranged to load the element under lateral bias on the latch such that the said element is released and retracted under the spring to a withdrawn inoperative position in consequence of the exertion laterally thereon of a relatively light pressure so as to enable desired changes in knitting to be made Without wholly removing the controller.

2. In a circular knitting machine according to claim 1, in which each iloat controlling element is accommodated in a housing in combination with a compression spring which is deformed in such a way as to impart sideways bias on the said element.

3. In a circular knitting machine according to claim 2, in which the latch of each controller element has a latching detent and is contained in a tubular housing within said spring which is a helical compression spring, the first helix of which is engaged with the said element and the last helix of which is offset from the axis of the spring so as to impart sideways bias on the element, and wherein the said latching detent engages with a part of the housing when the element `is fully depressed axially against the action of the spring.

4. In a circular knitting machine according to claim 1, wherein each float controller includes an electrical swith combined with it, said switch being designed for inclusion n an electrical stop motion circuit whereby release of any of the float controlling elements in consequence of lateral displacement results in immediate stoppage of the machine.

5. In a circular knitting machine according to claim 4, wherein each electrical switch comprises an insulator and a pair of metal contacts, one contact combined with the insulator and the other with the controller element for connection with an electrical stop motion circuit.

6. A float control unit for use in a circular knitting machine of the cylinder and dial type, comprising a housing, a yarn controlling element and a helical compression spring within the housing and about the yarn controlling element, the rst helix of which spring is xed to the controlling element, the last helix of thespring being offset from its axis and biased in a rst direction against the yarn controlling element, and a latching detent on the element, said detent arranged to engage the housing when the yarn controlling element is inan operative posi- 6 tion and a force is exerted thereon in the lirst direction by said spring, the side of the spring on the side of the yarn controlling element opposite from the detent engaging and pushing off the housing to exert said force on the yarn controlling element.

References Cited UNITED STATES PATENTS 3,226,954 1/ 1966 Fregeolle 66--125 3,323,333 6/1967 Vossen 66,--166 1,340,681 5/1920 Pigeon 66-131 1,668,435 5/ 1928 Urlaub 66-163 2,161,209 6/ 1939 Vossen 66-157 2,165,975 7/1939 Lawson et al. 66-157 2,285,237 y6/ 1942 Vossen 66-163 2,339,442 1/ 1944 Wachsman 66157 2,481,632 9/1949 Vossen 66-157 `2,672,036 3/ 1954 Wolf 66-157X WM. CARTER REYNOLDS, Primary Examiner U.S. Cl, XR, 66--1 57, 163 

